Chalcedony Ammonite from the middle Miocene around

from the middle Miocene around 12-16 million years ago

high shine mica and range in hue from nearly clear to classic sea green to deep blue

521 million years old

or the formation of equally thin layers of secondary minerals due to hydrothermal or other alteration

large calcite crystals and the dusting of fine gold from the pyrite is unique to specimens from this specific region of China and have not been found anywhere else

Chalcedony Ammonite from the middle Miocene aroundA silicone based mineral closely related to quartz and agate, Chalcedony has a unique crystalline structure that gives it an enormously variable appearance. This mineral forms in a similar fashion to agates and geodes but due to heat and pressure at the time of formation results in a distinct look and almost silky texture. Chalcedony can be found in a range of colors but most often occurs in semitransparent or white. It has a long archaeological